Force-pump for liquids



l w. HUNTER, FORCE PUMP FOR LIQUIDS.

APPLICATION FILED MAH.9,1920.

1,362,315, 4Pzllted Dec. 14, 1920.

2 SHEETS-SHEET I.

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FORCE PUMP FOR LIQUIDS.

APPLICATION FILED MAR. 9. 1920.

' 1,362,315. mamme. 14,1920.,

2 SHEETS*SHEET 2.

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UNITED STATES PATENT OFFICE.

WILLIAM HUNTER, or BtAcKPoon ENGLAND.

FQRGE-PUMP FOR LIQUIDS.

Application led March 9,

T all whom t may concer/n Be it known that I, VLLLIAM HUNTER, a subject of the King of Great Britain, residing at Blackpool, in the county of Lancaster and Kingdom of England, have invented a certain new and useful Improved Force- Iump for Liquids, of which the following 1s a specification.

This invention relates to an improved pump for liquids of the type in which an outer cylindrical member having suction and delivery ports cooperates with an inner cylinder having suction and delivery ports and with an innermost piston.

The object of the invention is to provide an arrangement which will be particularly applicable as a force pump for liquids by which it will be possible to obtain high pressures by an extremely simple apparatus, and it is a particular obj ect of the invention to reduce the number of the parts necessary for the construction of a simple pump. It is a further object of the invention to overcome the liability for =liquid to leak out ofthe chamber within the inner cylinder during the movement of said cylinder from one registering position to another. It is also an object of the invention to provide a pump in which sharp clearance can be obtained so that the suction and delivery ports are open full bore as long as possible.

To these and other ends, it will be apparent from the description, the invention comprises the combination of parts which will be understood from the following description of an illustrative example, and the scope of which will be defined in the appended claims.

In these drawings Figure l is a half sectional elevation (side view). y y

.F ig. 2 is a front elevation of the pump.

In these drawings, l is the outermost cylinder or casing provided with a suction portl 2 and a delivery port 3 communicating through suitable threaded connections'with a delivery pipe 4. These parts may be mounted within a container 5` which may contain the oil, although this may also be supplied in other ways to the suction opening.

Vithin the casing 1 there is an inner cylinder 6 provided with an enlarged head 7 and having a suction port 8 and a delivery port 9. This cylinder is open-ended at the bottom and it contains a false piston 10 which Specification of Letters Patent.

Patented Dec. 14;, 1920.

1920. serial 110.364.489.

is very accurately machined to tit within the cylinder. This false piston l0 projects through the base 11 mounted withinthe container' 5.. This base plate 1l has also mounted thereon a flanged piece 12 land the outer cylinder 1, but thearrangement is such that air can be admitted beneath the bottom of the cylinder 6 when it rises about the false piston 140A; the fit between the false piston lO and the cylinder 6 is so close-that no substantial escape of oil can take place. Within the cylinder 6 there is mounted aV tightly fitting piston 13. i

The piston and innerV cylinder are reciprocated by suitable mechanism of which a specific illustration is shown in the drawings and will be described later, in such manner as to perform the following series of operations 1. While the opening 8 registers with the opening 2, the piston 13 is caused to rise and suck in a charge of oil. During this time, it is preferazble'that the, cylinder 6 shall be caused to dwell so as to maintain the ports 2 and 8 in full bore engagement, but this is not absolutely essential, particularly in cases when there is very little clearance -between the inlet and outlet ports of the cylinder so that the whole travel of the cylinder is slight in comparison with the `size of the ports.

2. In the second position, the piston is caused to dwell and the cylinder moves downward into the position shown in Fig. 1. During this movement, as the piston 13 is caused to dwell and as the false piston 10 is stationary, there is no tendency to compression or expansion of the oil contained in the space between the piston and false piston as would be the lcase if the cylinder werel employed with av closed end as has been proposed hitherto. If such a cylinder is employed having a closed end, it will be clear that either the apparatus .will be inoperative, or that leakage must take place either inward or outward at a time when the piston is stationary and when neither of the ports S and 9 is in engagement with the ports 2' and 3. The false piston 10 is an important feature of my invention since it enables these difficulties to be overcome by allowing movement of the cylinder without causing compression or expansion of the oil contained therein.

3. When the port 9 registers with the port 3, the cylinder is then preferably caused to dwell and the piston 13 is forced downward thus discharging the oil through port 3 and pipe 4. Fig. 1 shows the piston near the bottom of its downward stroke.`

4. The piston is then caused to dwell and the cylinder 6 is moved upward till port 8 registers with port 2. A. Y

It will be seen that by providing a dwell in the movement of the cylinder and piston, it is possible to avoid leakage. This object can be obtained by providing a dwell in the movement of the piston alone, but in addition it is also preferable to cause'the cylinder to dwell in order to secure full bore engagement of the ports as above described.

In practice, I find that the above operations can be obtained in the most simple and positive manner by employing rollers engaging cam grooves on opposite sides of the same cam disk, and this arrangement has the advantage of great simplicity, so that onlytfew parts are required which can be assembledvery rapidly indeed. From the above description, it will be'seen that each cam groove should have two opposite quarters concentric to allow for the dwell periods A and two opposite quarters eccentric to provide for the upwardand downward movements, and further one cam groove should lead the other by one quarter of the revolution. Tn Fig. 1, the dotted lines show the cam groove 14 within which is arranged a roller 15 attached to the piston. The full linesfshow the camV groove 16 within which is mounted the roller 17 connected with the flanged head 7. It will be seen that these grooves are on opposite sides of the cam disk 18 which is mounted on a square shaft 19 journaled at 2O and 21 within the casing 5. This shaft may be rotated mechanically or by means of a hand wheel 22 having a handle 23 and ratchet teeth engaging with a pawl 24. The roller 15 is mounted on a head 27 Y at the top of the piston 13 while the roller 17 is carried. on a bracket 28 projecting up' ward from the flange 7 25` is a pin projecting downward from the flange 7 toengage with a vertical groove 26 on thecasing 1 in order to prevent relative rotation between the inner and outer cylinders.V Y

Tt' will be seen therefore that a valveless pump, especially valuable as a force pump, has been provided having means to maintan a constant volume of liquid in the inner cylinder beneath the piston 13, while this cylinder is moving `'from registry between the inlet ports to registry between the outlet ports.

declare that what I claim is 1. A pump having a ported outer cylinder, a ported open-ended inner cylinder having a substantial clearance between inlet and outlet registry of said ports and an innermost piston in combination with a false piston within the inner cylinder and means to reciprocate the innermost pistonallowing a dwell while the inner cylinder is moving;

2. A. pump having a ported outer cylinder, a ported open-ended inner cylinder having a substantial clearance between inlet and outlet registry of said ports and `an innermost piston in combination with means to maintain a constant volume of liquid in the inner cylinder while the cylinder is moving from registry between inlet ports to registry between outlet ports.

3. A pump having a ported outer cylinder, a ported open-ended inner cylinderand an innermost piston in combination with a false piston within the inner cylinder, means to reciprocate said cylinder and means to reciprocate the innermost piston allowing a dwell while the linner cylinder is moving 4. A pump having a ported outer cylinder, a ported open-ended inner cylinder and an innermost piston in combination with a Jfalse piston within the inner cylinder and means to reciprocate the inner cylinder and innermost piston in such manner that the piston dwells while the cylinder is moving, and vice versa.

5. A pump Ahaving a ported outer cylinder, a ported open-ended inner cylinder and an innermost piston in combination with rollers engaging in cam grooves on opposite lsides of a cam disk to reciprocate the inner cylinder and the piston.

6. A pump having ported outer cylinder. a ported open-ended inner cylinder, and an innermost piston in combination with a false piston withinthe inner cylinder and means to reciprocate the'innermost piston including cam means so Varranged that a concentric movement of the cam takes place while the inner cylinder is moving.

In witness whereof l have hereunto signed my name this 16th day of February, 1920, in the presence of twosubscribing witnesses.

Y WILLIAM HUNTER..

Witnesses HAROLD E. Po'rrs, J. MoLnoHLAN. 

